1. Field of the Invention
This invention relates to release apparatus for cameras, and, more particularly, to release apparatus for automatically actuating a camera release.
2. Description of the Prior Art
The conventional automatic shooting method is to use a beam projector and a receptor therefor arranged so that the path of the beam from the projector to the receptor lies in the field of view of the camera. When an object, for example, an animal, comes across the path of the beam, the camera is automatically released to effect automatic shooting of the object. Such an apparatus is more fully explained by using FIG. 1.
In FIG. 1, A denotes the beam projector, B the light receptor, and C the camera. The beam projector A comprises a light emitting circuit 1 for driving a light-emitting element 2, for example, LED. Rays of light from the energized LED 2 are collimated by a lens 3. A beam from the projector A is directed to a condenser lens 4 in the receptor B. Light emerging from the lens 4 passes through a filter 5 to a photosensitive element 6 such as a photo-transistor. The output of the photo-transistor 6 is processed by a light receiving circuit 7 to obtain an electrical signal representing whether or not the beam is intercepted by an object 11. The electrical signal after having been amplified by an amplifier circuit 8 is applied to a detector circuit 9. With this apparatus A, B, as the object 11 is moving in a direction of arrow, a, it is, therefore, at a time when it enters the beam, that the output of the processing circuit 7 lowers sharply. By detecting this change, the detector circuit 9 actuates a release of the camera C.
This conventional type of release apparatus allows whatever can block light at any rate to cause a shot to be taken when it enters in between the beam projector A and the receptor B. Hence, there has been a drawback that despite the intention of the photographer being to shoot, for example, a wild animal, even a leaf falling into the beam can trigger the camera, resulting in a large percentage of undesired shots being taken.